This is a Fowler crane from the 1940's based on an IH Farmall farm tractor with a front loading bucket attachment. These cranes were built on an assortment of farm tractors in Melbourne. I also found a photo from the Melbourne Museum of a Massey Harris with a similar set-up. May be basic but would have been easier and more efficient than shovelling a load of gravel onto a truck by hand!
My one concern would be.... when something let loose what a head ache, still kinda neat though